Drill pipe protector

ABSTRACT

MY INVENTION IS A DRILL PIPE PROTECTOR COMPRISING A SPACING MEANS AND AN ATTACHING MEANS AND CHARACTERIZED BY A MEANS   FOR INDUCING A COMPRESSIVE STRESS AT THE WEARING SURFACE TO CLOSE AND SEAL CUTS.

United States Patent inventor Arthur H. Hopmans 1753 N. Dillon St., Los Angeles, Calif. 90026 Appl. No. 848,857 Filed Aug. 11, 1969 Patented June 28, 1971 DRILL PIPE PROTECTOR 5 Claims, 1 Drawing Fig.

US. Cl 308/4A, 175/325 Int. Cl F160 1/26 Field of Search 308/4 (A);

[56] References Cited UNITED STATES PATENTS 2,693,986 11/1954 Phreaner 308/4A 2,628,134 2/1953 Williams et al. 308/4A Primary Examiner-Martin P. Schwadron Assistant ExaminerR. Lazarus ABSTRACT: My invention is a drill pipe protector comprising a spacing means and an attaching means and characterized by a means for inducing a compressive stress at the wearing surface to close and seal cuts.

JUN28I97I 7 PATENTED 3 588,199

{wax W 1N VENTOR DRILL PIPE PROTECTOR In the drilling of deep holes such as oil wells the drill stem of pipe, during rotation, tends to whip laterally into abrasive engagements with walls of the hole. It is customary to prevent such abrasive engagement by drill pipe protectors, having an elastomer outer surface, attached to the drill pipe as a means for spacing the drill pipe from the walls of the hole. The sad outer surface is subject to cutting due to abrasion against the walls of the hole and sharp rock chips flowing from the bottom of the well and is also subject to chemical attack ofoxygen and petroleum products in contact with the exposed elastomer wearing surface. The chemical attack reduces the resistance to abrasive cutting and the abrasive cutting exposes new and large surface areas to chemical attack. In prior protectors the wearing surface is in tension, due to the attaching means typically employed, so that cuts tend to gape open permitting further penetration of the cutting edge and exposing the cut walls to chemical contact.

It is an object of my invention to provide drill pipe protectors wherein the typical attaching means, of prior protectors, will not cause cuts in the wearing surface to gape open.

It is also an object of my invention to provide for the sealing of cuts on the wearing surface whether the attaching means is: a constricting, elastic annular band; a bonded interface with the drill pipe such as cement or vulcanization; a mechanical reinforcement of the spacing means; a constricting elastic band to which the spacing means is bonded.

In general, I achieve my objects by a compressive stress at the wearing surface induced by elastically deforming the elastomer spacing means and maintaining the deformation by bonding the spacing means as by cementing or vulcanizing it to the attaching means.

In a more particular adaptation of my invention I achieve these objects by so molding and shaping the protector that the final deformation and installation of the protector results in a compressive stress along the wearing surface.

Without limiting my invention I shall refer to the drawing to describe one of its presently preferred embodiments.

The sole FIGURE is a side elevational view of my improved protector constricted about a conventional drill pipe with a portion in section,

Referring now to the drawing, 5 denotes a conventional drill pipe as used in the drilling of an oil well. 6 denotes my drill pipe protector installed on the pipe.

The protector 6 comprises: an annular body 7 of elastomeric material such as natural or synthetic rubber compositions, many of which are well known in the art, which in unstressed condition is much smaller in diameter than the drill pipe, in order that it may be forced tightly onto the drill pipe to create a tension stress and to constitute an attachment means for this embodiment; a second annular by 8 also of elastomeric material which in unstressed condition has a larger diameter than the installed diameter shown and constitutes the spacing means; a bonded interface 9 which by holding the spacing means 8 to a reduced diameter constitutes a compressive stress means whereby cuts inflicted on the outside diameter of the drill pipe protector are forced closed to seal out ambient chemicals and frictionally inhibit further penetration of cutting edges; an adhesive bond 10 constitutes an additional attaching means.

Iclaim:

1. A drill pipe protector comprising a spacing means having a wearing surface and an attaching means within said spacing means, wherein the improvement comprises a compressive stress means located between said spacing means and said attaching means for sealing cuts on the wearing surface.

2. The protector of claim 1 wherein the compressive stress means is an elastic reduction in at least one of the dimensions of the spacing means.

3. The protector of claim 1 wherein the compressive stress means is a bonded interface holding the spacing means to a reduced diameter.

4. The protector of claim I wherein an elastic change in at least 1 dimension is maintained by bonding the spacing means to the attaching means.

5. The protector of claim 1 wherein the compressive stress means is a reduction in the normal diameter of the spacing means. 

